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<h2><a href="closure_goog_storage_storage.js.html">storage.js</a></h2>

<pre class="prettyprint lang-js">
<a name="line1"></a>// Copyright 2011 The Closure Library Authors. All Rights Reserved.
<a name="line2"></a>//
<a name="line3"></a>// Licensed under the Apache License, Version 2.0 (the &quot;License&quot;);
<a name="line4"></a>// you may not use this file except in compliance with the License.
<a name="line5"></a>// You may obtain a copy of the License at
<a name="line6"></a>//
<a name="line7"></a>//      http://www.apache.org/licenses/LICENSE-2.0
<a name="line8"></a>//
<a name="line9"></a>// Unless required by applicable law or agreed to in writing, software
<a name="line10"></a>// distributed under the License is distributed on an &quot;AS-IS&quot; BASIS,
<a name="line11"></a>// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<a name="line12"></a>// See the License for the specific language governing permissions and
<a name="line13"></a>// limitations under the License.
<a name="line14"></a>
<a name="line15"></a>/**
<a name="line16"></a> * @fileoverview Provides a convenient API for data persistence using a selected
<a name="line17"></a> * data storage mechanism.
<a name="line18"></a> *
<a name="line19"></a> */
<a name="line20"></a>
<a name="line21"></a>goog.provide(&#39;goog.storage.Storage&#39;);
<a name="line22"></a>
<a name="line23"></a>goog.require(&#39;goog.json&#39;);
<a name="line24"></a>goog.require(&#39;goog.json.Serializer&#39;);
<a name="line25"></a>goog.require(&#39;goog.storage.ErrorCode&#39;);
<a name="line26"></a>goog.require(&#39;goog.storage.mechanism.Mechanism&#39;);
<a name="line27"></a>
<a name="line28"></a>
<a name="line29"></a>
<a name="line30"></a>/**
<a name="line31"></a> * The base implementation for all storage APIs.
<a name="line32"></a> *
<a name="line33"></a> * @param {!goog.storage.mechanism.Mechanism} mechanism The underlying
<a name="line34"></a> *     storage mechanism.
<a name="line35"></a> * @constructor
<a name="line36"></a> */
<a name="line37"></a>goog.storage.Storage = function(mechanism) {
<a name="line38"></a>  this.mechanism = mechanism;
<a name="line39"></a>  this.serializer_ = new goog.json.Serializer();
<a name="line40"></a>};
<a name="line41"></a>
<a name="line42"></a>
<a name="line43"></a>/**
<a name="line44"></a> * The mechanism used to persist key-value pairs.
<a name="line45"></a> *
<a name="line46"></a> * @type {goog.storage.mechanism.Mechanism}
<a name="line47"></a> * @protected
<a name="line48"></a> */
<a name="line49"></a>goog.storage.Storage.prototype.mechanism = null;
<a name="line50"></a>
<a name="line51"></a>
<a name="line52"></a>/**
<a name="line53"></a> * The JSON serializer used to serialize values.
<a name="line54"></a> *
<a name="line55"></a> * @type {goog.json.Serializer}
<a name="line56"></a> * @private
<a name="line57"></a> */
<a name="line58"></a>goog.storage.Storage.prototype.serializer_ = null;
<a name="line59"></a>
<a name="line60"></a>
<a name="line61"></a>/**
<a name="line62"></a> * Set an item in the data storage.
<a name="line63"></a> *
<a name="line64"></a> * @param {string} key The key to set.
<a name="line65"></a> * @param {*} value The value to serialize to a string and save.
<a name="line66"></a> */
<a name="line67"></a>goog.storage.Storage.prototype.set = function(key, value) {
<a name="line68"></a>  if (!goog.isDef(value)) {
<a name="line69"></a>    this.mechanism.remove(key);
<a name="line70"></a>    return;
<a name="line71"></a>  }
<a name="line72"></a>  this.mechanism.set(key, this.serializer_.serialize(value));
<a name="line73"></a>};
<a name="line74"></a>
<a name="line75"></a>
<a name="line76"></a>/**
<a name="line77"></a> * Get an item from the data storage.
<a name="line78"></a> *
<a name="line79"></a> * @param {string} key The key to get.
<a name="line80"></a> * @return {*} Deserialized value or undefined if not found.
<a name="line81"></a> */
<a name="line82"></a>goog.storage.Storage.prototype.get = function(key) {
<a name="line83"></a>  var json = this.mechanism.get(key);
<a name="line84"></a>  if (goog.isNull(json)) {
<a name="line85"></a>    return undefined;
<a name="line86"></a>  }
<a name="line87"></a>  /** @preserveTry */
<a name="line88"></a>  try {
<a name="line89"></a>    return goog.json.parse(json);
<a name="line90"></a>  } catch (e) {
<a name="line91"></a>    throw goog.storage.ErrorCode.INVALID_VALUE;
<a name="line92"></a>  }
<a name="line93"></a>};
<a name="line94"></a>
<a name="line95"></a>
<a name="line96"></a>/**
<a name="line97"></a> * Remove an item from the data storage.
<a name="line98"></a> *
<a name="line99"></a> * @param {string} key The key to remove.
<a name="line100"></a> */
<a name="line101"></a>goog.storage.Storage.prototype.remove = function(key) {
<a name="line102"></a>  this.mechanism.remove(key);
<a name="line103"></a>};
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